1. Field of the Invention
The present invention relates to a gas shielded arc-welding flux cored wire (hereinafter also referred to as "the fluxed cored wire") for used in a mild steel, a high strength steel, and a low alloy steel which are used for ships, bridges, steel frames, etc., in particular to a gas shielded arc-welding flux cored wire which has excellent welding usability even when used on a high welding current condition in order to improve the welding work efficiency.
2. Prior Art
There are various flux cored wires used for fillet welding which has been proposed, e.g. in Japanese Publication of unexamined application (Kokai) No. 61-147993 and Japanese Publication of unexamined application (Kokai) No. 3-294092. On this occasion, fillet welding has been demanded to further increase in speed. Also, the flux cored wire used for fillet welding is generally subjected to a measure to prevent pits or worm holes being formed on the bead due to a rust preventive primer applied on a steel structure during its production. However, the high-speed-horizontal fillet welding is dramatically affected by the kind, and the thickness of the primer applied on the steel plate, which provides a problem related to resistance to primer. Besides, obtaining a target leg length corresponding to the high-speed of the welding necessarily provides a high electric current welding condition, which provides problems of the bead convexity, comfortable shape of the toe portion, and deterioration of the bead appearance and the slag peeling properties due to undercut and slag seizure.
The all position welding flux cored wires have been most widely used since they can perform the all position welding such as a flat position, a horizontal position, an overhead position, and a vertical position welding; however, they are demanded to prevent the metal running in the vertical position welding and to be available on a wide range welding condition, particularly when used on the high welding current condition. The metal running in the vertical position welding provides such problems of the conformability of the bead toe portion, the bead appearance, and the slag peeling properties.